Method of transmitting and receiving control information based on spatial-multiplexing gain

ABSTRACT

A control information transmission and reception method based on a spatial-multiplexing gain, are provided. The control information may be transmitted by obtaining the spatial-multiplexing gain using an E-PDCCH region, and thus, a transmission efficiency of the control information may be improved. The common control information used for decoding the E-PDCCH may be transmitted via a PDCCH, and thus, a base station supporting both a general terminal and an enhanced terminal may effectively transmit the control information. Information associated with an indicator indicating whether the E-PDCCH is to be used during a subsequent resource allocation period may be transmitted, and thus, whether decoding with respect to the E-PDCCH is to be performed during the subsequent allocation period may be determined.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit under 35 U.S.C. §119(a) of KoreanPatent Application No. 10-2010-0032073, filed on Apr. 7, 2010, in theKorean Intellectual Property Office, the entire disclosure of which isincorporated herein by reference for all purposes.

BACKGROUND

1. Field

The following description relates to a method of transmitting controlinformation by a base station, and more particularly, to a method of abase station simultaneously supporting two types of terminals, and areception method of receiving the control information.

2. Description of Related Art

To simultaneously support a terminal in a general communication systemand a terminal in an enhanced communication system, a control channelmay be configured to enable the terminal in the enhanced system toobtain information associated with a broadcast channel allocated to acorresponding terminal. In addition, the terminal may obtain resourceinformation for the control channel and information used for decoding.

SUMMARY

In one general aspect, there is provided a transmission method,comprising allocating resource blocks (RBs) to at least one data streamtransmitted via an enhanced-physical downlink shared channel (E-PDSCH),generating control information for each of the RBs, allocating thecontrol information for each of the RBs to a resource region for anenhanced-physical downlink control channel (E-PDCCH), and performing oneof beamforming of the control information for each of the RBs based onthe resource region, spatial-multiplexing of the control informationassociated with the RBs based on the resource region, andbeamforming-based spatial-multiplexing of the control informationassociated with the RBs based on the resource region.

The transmission method may further comprise generating an indicatorindicating whether the E-PDCCH is used in a subsequent resourceallocation period, wherein the control information includes theindicator.

The allocating of the control information may comprise allocating thecontrol information to enable the resource region used for transmittingthe control information to be a portion of a physical resource used bythe E-PDSCH.

The transmission method may further comprise generating common controlinformation used for decoding the control information for each of theRBs, and transmitting the common control information via a physicaldownlink control channel (PDCCH).

The generating may comprise generating at least one of informationassociated with a range of the resource region to which the controlinformation for each of the RBs is allocated, information associatedwith a range of the RBs to which the at least one data stream isallocated, a group terminal identifier for a terminal where decoding ofE-PDCCH is to be performed, information associated with a location and apilot pattern for demodulation, information associated with a poweroffset, and information associated with a transport format.

The allocating of the RBs may comprise allocating a portion of all theRBs for the at least one data stream to the at least one data stream,the allocating of the control information may comprise allocating thecontrol information using a portion of an entire resource region for theE-PDCCH, and the generating of the common control information maycomprise generating the control information including the informationassociated with the portion of all the RBs and information associatedwith the portion of the entire resource region.

The transmission method may further comprise allocating the commoncontrol information to a predetermined resource region for the PDCCH,wherein both a type 1 terminal and a type 2 terminal successfully decodethe information received via the PHCCH, and the type 2 terminal issupported by a different type of system than the type 1 terminal.

The type 1 terminal may be supported by an enhanced system and the type2 terminal may be supported by a general system.

The transmission method may further comprise generating common controlinformation used for decoding the control information for each of theRBs, and transmitting the common control information via a predeterminedbroadcast channel.

The generating may comprise generating at least one of informationassociated with a range of the resource region to which the controlinformation for each of the RBs is allocated, information associatedwith a range of the RBs to which the at least one data stream isallocated, a group terminal identifier for a terminal where decoding ofE-PDCCH is to be performed, information associated with a location and apilot pattern for demodulation, information associated with a poweroffset, and information associated with a transport format.

The allocating of the RBs may comprise allocating a portion of all theRBs for the at least one data stream to the at least one data stream,the allocating of the control information may comprise allocating thecontrol information using a portion of an entire resource region for theE-PDCCH, and the generating of the common control information maycomprise generating the control information including the informationassociated with the portion of all the RBs and information associatedwith the portion of the entire resource region.

The generating of the control information may generate at least one ofinformation associated with a range of the RBs to which the at least onedata stream is allocated, information associated with a number of the atleast one data stream, a terminal identifier of a terminal to whichcontrol information is allocated, location information and a pilotpattern for demodulation, information associated with a power offset,information associated with a co-scheduled terminal, H-ARQ information,and information associated with a modulation and coding scheme.

The allocating of the control information may comprises allocating thecontrol information to enable the resource region for the E-PDCCH tooverlap a region of the RBs to which the at least one data stream isallocated.

When a type 1 terminal and a type 2 terminal exist, the type 1 terminalmay succeed in decoding information received via the E-PDCCH and thetype 2 terminal may not decode or may fail in decoding the informationreceived via the E-PDCCH, and the type 2 terminal may be supported by adifferent type of system than the type 1 terminal.

The type 1 terminal may be supported by an enhanced system and the type2 terminal may be supported by a general system.

In another aspect, there is provided a reception method, comprisingextracting a previous indicator included in multiple pieces of controlinformation received in a previous resource allocation period,determining, using the previous indicator, a channel through whichmultiple pieces of target control information are transmitted, fromamong an E-PDCCH and a PDCCH, and decoding the multiple pieces of targetcontrol information based on the determination.

When the determination determines that the multiple pieces of targetcontrol information are transmitted through the PDCCH, the decoding maycomprise decoding the multiple pieces of target control informationbased on a radio resource for the PDCCH.

When the determination determines that the multiple pieces of targetcontrol information are transmitted through the E-PDCCH, the method mayfurther comprise receiving common control information of the multiplepieces of target control information via one of the PDCCH and apredetermined channel, and the decoding may comprise decoding themultiple pieces of target control information based on the commoncontrol information.

The decoding may comprise decoding the common control information basedon a group terminal identifier that is commonly allocated to allterminals in an enhanced system.

When each of the multiple pieces of target control informationcorresponds to a respective data stream and the determination determinesthat the multiple pieces of target control information are transmittedvia the E-PDCCH, the decoding may comprise decoding each of the multiplepieces of target control information based on a signal to noise ratio(SNR) of corresponding target control information.

The decoding may comprise determining a decoding sequence for themultiple pieces of target control information based on an SNR of eachtarget control information, and continuously decoding the multiplepieces of target control information until a desired number of targetcontrol information is successfully decoded.

The method may further comprise decoding, based on the multiple piecesof decoded target control information, at least one data stream receivedfrom the E-PDSCH or a physical downlink shared channel (PDSCH).

When the determination determines that the multiple pieces of targetcontrol information are transmitted via the E-PDCCH, the multiple piecesof target control information may include information associated withRBs allocated to at least one data stream, and the at least one datastream may be transmitted via the E-PDSCH.

When the multiple pieces of target control information are allocated tothe same resource region, the resource region is for the E-PDCCH, andthe multiple pieces of target control information may be one ofspatial-multiplexed, beamforming-processed, and a beamforming-basedspatial-multiplexed based on the same resource region.

When a type 1 terminal and a type 2 terminal exist, the type 1 terminalmay succeed in decoding information received via the E-PDCCH and thetype 2 terminal may not decode or may fail in decoding the informationreceived via the E-PDCCH, and the type 2 terminal may be supported by adifferent type of system than the type 1 terminal.

The type 1 terminal may be supported by an enhanced system and the type2 terminal may be supported by a general system.

In another aspect, there is provided a reception method, comprisingreceiving control information that is one of beamforming-processed,spatial-multiplexed, and beamforming-based spatial-multiplexed, via anE-PDCCH, decoding the control information based on a blind decodingscheme, recognizing, based on the decoded control information, RBsallocated to least one data stream that is transmitted via the E-PDSCH,and receiving at least one data stream based on the RBs allocated to theat least one data stream.

When a type 1 terminal and a type 2 terminal exist, the type 1 terminalmay succeed in decoding information received via the E-PDCCH and thetype 2 terminal may not decode or may fail in decoding the informationreceived via the E-PDCCH, and the type 2 terminal may be supported by adifferent type of system than the type 1 terminal.

The type 1 terminal may be supported by an enhanced system and the type2 terminal may be supported by a general system.

In another aspect, there is provided a transmitter, comprising ascheduler to allocate RBs to at least one data stream transmitted via anE-PDSCH, to generate control information for each of the RBs, and toallocate the control information for each of the RBs to a resourceregion for an E-PDCCH, and a spatial-multiplexer to perform one ofbeamforming, spatial-multiplexing, and beamforming-basedspatial-multiplexing with respect to each of the RBs, based on theresource region.

In another aspect, there is provided a receiver, comprising a memory tostore a previous indicator included in control information received in aprevious resource allocation period, and a processor to determine, basedon the previous indicator, a channel through which target controlinformation is transmitted, from among an E-PDCCH or a PDCCH, and todecode the target control information based on the determination.

Other features and aspects may be apparent from the followingdescription, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart illustrating an example of a method oftransmitting control information based on a spatial-multiplexing gain.

FIG. 2 is a diagram illustrating an example of a dynamic format of acontrol channel transmission frame to support an enhanced terminal.

FIG. 3 is a diagram illustrating a second example of a dynamic format ofa control channel transmission frame to support an enhanced terminal.

FIG. 4 is a diagram illustrating a third example of a dynamic format ofa control channel transmission frame to support an enhanced terminal.

FIG. 5 is a flowchart illustrating an example of a control informationtransmission method of a base station supporting the dynamic format ofthe control channel transmission frame of FIG. 2.

FIG. 6 is a diagram illustrating an example of a semi-static format of acontrol channel transmission frame to support an enhanced terminal.

FIG. 7 is a flowchart illustrating an example of a control informationtransmission method of a base station supporting the semi-static formatof the control channel transmission frame of FIG. 6.

FIG. 8 is a diagram illustrating an example of a format of atransmission frame where a control channel element (CCE) used fortransmitting an E-PDCCH and an RB used for transmitting an E-PDSCH aremapped.

FIG. 9A is a flowchart illustrating an example of a control informationreception method of an enhanced terminal.

FIG. 9B is a flowchart illustrating a process of decoding an E-PDCCHbased on a blind decoding scheme.

FIG. 10 is a diagram illustrating an example of a transmitter thatsimultaneously supports a general terminal and an enhanced terminal.

FIG. 11 is a diagram illustrating an example of an enhanced terminal.

Throughout the drawings and the description, unless otherwise described,the same drawing reference numerals should be understood to refer to thesame elements, features, and structures. The relative size and depictionof these elements may be exaggerated for clarity, illustration, andconvenience.

DESCRIPTION

The following description is provided to assist the reader in gaining acomprehensive understanding of the methods, apparatuses, and/or systemsdescribed herein. Accordingly, various changes, modifications, andequivalents of the methods, apparatuses, and/or systems described hereinmay be suggested to those of ordinary skill in the art. Also,descriptions of well-known functions and constructions may be omittedfor increased clarity and conciseness.

As described herein, a base station may support a terminal based on anenhanced communication standard while continuously supporting a terminalin a general communication system. The base station may effectivelytransmit control information and the enhanced terminal may effectivelyreceive the control information. The examples described herein may beapplicable to a terminal and a base station in an enhanced system, forexample, a 3rd Generation Partnership Project Long Term Evolutionadvanced system (LTE Advanced). The advanced system is more enhancedthan the general system such as a 3GPP Long Term Evolution (3GPP LTE)general system. Although the examples described herein are based on anenhanced terminal of a 3GPP LTE advanced system (LTE Advanced) whilecontinuously supporting a terminal of the 3GPP LTE system, it should beunderstood that this is merely for purposes of example. Accordingly, thetechnology described herein is not limited to the LTE Advanced system,and other advanced systems may be applicable.

A data stream may be one-to-one mapped to a layer corresponding to thedata stream and thus, both terms may be used together throughout theexamples described herein.

FIG. 1 illustrates an example of a method of transmitting controlinformation based on a spatial-multiplexing gain.

Referring to FIG. 1, a base station may transmit control information foran enhanced terminal based on a transmission method. In this example, anenhanced terminal may be referred to as a type 1 terminal that issupported by a LTE Advanced system and a general terminal may bereferred to as a type 2 terminal that is supported by a 3GPP LTE system.

The base station may allocate resource blocks (RBs) to at least one datastream transmitted via an enhanced-physical downlink shared channel(E-PDSCH), in 110. For example, the base station may allocate only someof the RBs out of all the RBs to the at least one data stream. In anexample where the number of available RBs to be allocated for datastreams is limited, the base station may reduce an amount of controlinformation.

The base station generates control information, such as downlink controlinformation (DCI) for the E-PDSCH, for each of the RBs, in 120.

In 130, the base station allocates the control information for each ofthe RBs to the same resource region such as an enhanced-physicaldownlink control channel (E-PDCCH). As an example, the enhanced terminalmay succeed in decoding information received via the E-PDCCH, and thegeneral terminal may fail to decode the information received via theE-PDCCH. As another example, the enhanced terminal and the generalterminal may both succeed in decoding information received via aphysical downlink control channel (PDCCH). For example, a demodulationreference signal (DM-RS) may be a dedicated pilot. Accordingly, aterminal that may receive the DM-RS may be the enhanced-terminal and aterminal that may not receive the DM-RS may be the general terminal.

As an example, the control information may be allocated using only aportion of the entire resource region for the E-PDCCH. A resource regionwhere control information is allocated is limited and thus, an amount ofcommon control information may be reduced.

For example, the control information may be allocated to the resourceregion for the E-PDCCH to enable the resource region used fortransmitting the control information to be a portion of a physicalresource used by the E-PDSCH, instead of allocating the entire resourceregion for the E-PDCCH.

The base station performs spatial-multiplexing on the controlinformation for each of the RBs based on the same resource region, in140. For example, the E-PDCCH of the same physical resource may bespatially multiplexed through a beamforming process. Thus, thetransmission efficiency of control information transmitted to a singleterminal or to a plurality of terminals may be improved.

Although it is not illustrated in FIG. 1, the base station may performbeamforming of the control information for each of the RBs or mayperform spatial-multiplexing of the control information for each of theRBs, based on the same resource region.

Multiple pieces of control information, for example, multiple pieces ofDCI for the E-PDSCH, may share the same frequency resource and the sametime resource for the E-PDCCH. Accordingly, multiple pieces of controlinformation may be transmitted after being one of spatial-multiplexed,beamforming-processed, and beamforming-based spatial-multiplexed.

In this example, a plurality of control information streams that may beone of spatial-multiplexed, beamforming performed, and beamforming-basedspatial-multiplexed may be transmitted to different terminals or to asingle terminal. As another example, a single control information streammay be transmitted to a single terminal that may obtain a beamforminggain through the beamforming process. The control information streams ofthe enhanced system may have the same control channel element (CCE). Forexample, the DCI for the E-PDSCH may be one of beamforming-performed,spatial-multiplexed based on the same time resource and the samefrequency resource, and beamforming-based spatial-multiplexed based onthe same time resource and the same frequency resource, and may have thesame CCE.

Content of Control Information

Control information, for example, the DCI for the E-PDSCH, may includeinformation as given below, in order to support a multiple user-multipleinput multiple output (MU-MIMO) transmission in the E-PDSCH.

-   -   a terminal identifier of a terminal where DCI for the E-PDSCH is        allocated, for example, the terminal identifier may be a cell        Radio Network Temporary Identifier (C-RNTI), and the C-RNTI may        be scrambled to a cyclic redundancy check (CRC);    -   a bitmap of RBs used for transmitting the E-PDSCH or frequency        resource information used for transmitting the E-PDSCH, for        example, a range of RBs where at least one data stream        transmitted via the E-PDSCH is allocated;    -   a number of symbols and a location of an orthogonal frequency        division multiplexing (OFDM) used for transmitting the E-PDSCH        or time resource information used for transmitting the E-PDSCH,        for example, a range of RBs where at least one data stream        transmitted via E-PDSCH is allocated;    -   information associated with a location and a pilot pattern, such        as a reference signal (RS) pattern, to be used for demodulation;    -   power offset;    -   a number of layers of the E-PDSCH, for example, a number of at        least one data stream transmitted via the E-PDSCH, and        information associated with the allocated layer;    -   information associated with a co-scheduled terminal;    -   other information used for decoding the E-PDSCH;    -   information associated with an indicator, such as 1 Bit        Indicator, indicating a channel to be used for transmitting        resource allocation information from among a PDCCH and the        E-PDCCH, during a subsequent allocation period; and the like.

Examples of the other information for decoding the E-PDCCH may include,for example, hybrid automatic repeat request (H-ARQ) information, suchas a H-ARQ process ID, a new data indicator, a redundancy version, andthe like, and may include information associated with a transportformat, such as modulation and coding schemes.

When the indicator is transmitted, effects that may improve atransmission efficiency of a control channel may be provided.

For example, the base station may select a control channel having arelatively high transmission efficiency from among the PDCCH and theE-PDCCH to perform transmission, and thus, the efficiency of a controlchannel may increase. Based on a channel environment of each terminal, anumber of terminals, a type of control information to be transmitted,and the like, the transmission using the PDCCH may be may be moreeffective in comparison to the transmission using the E-PDCCH. Terminalsto be scheduled may be different for each frame, and thus, theefficiency may vary. Therefore, when the indicator is used, the basestation may freely select a control channel to be used for transmissionin order to minimize an overhead of entire control channels, and thus, atransmission efficiency of the entire control channels may be improved.

The information associated with the indicator may be used to decreasethe decoding complexity of a terminal, and a further description thereofis provided herein.

Common Control Information

When a control channel of an enhanced-system is supported and a controlchannel of a general system is also supported, a base station mayeffectively transmit, to a terminal, information used for decoding theenhanced control channel, for example, resource information for theenhanced control channel, a modulation scheme, a channel coding scheme,and the like.

For example, the base station may transmit, to each terminal via thePDCCH, common control information, for example, DCI for the E-PDCCH,used for decoding control information transmitted via E-PDCCH. Anenhanced terminal may decode the PDCCH to obtain the common controlinformation, and may decode the E-PDCCH based on the common controlinformation. As an example, the E-PDCCH may be located in a region ofthe PDSCH based on a structure of a frame of a general system, such as a3GPP LTE system. When the E-PDCCH is decoded, control information, suchas resource allocation information for each terminal and the like, maybe obtained.

For example, the common control information used for decoding theE-PDCCH that corresponds to each of enhanced terminals in a LTE Advancedsystem may not received by each terminal and may be commonly received byenhanced terminals only that may decode the E-PDCCH. For example, thecommon control information may include a location of a resource of theentire E-PDCCH, a number of resources allocated for transmitting theE-PDCCH, a number of spatial-multiplexed layers, and the like. Theinformation may be transmitted based on a group terminal identifier,such as a group C-RNTI, which is commonly shared by all the enhancedterminals. The group terminal identifier used for the described purpose,for example, a FFF4-FFFC: that is reserved for future use, may bepredetermined in a system, or the base station may report the groupterminal identifier to a corresponding terminal via a separate broadcastchannel. Accordingly, the enhanced terminal may obtain informationassociated with a corresponding group C-RNTI before decoding theE-PDCCH.

The common information, for example, DCI for the E-PDCCH, may includeinformation used for decoding the E-PDCCH as given below.

-   -   a group terminal identifier, such as a Group C-RNTI, for        example, the group terminal identifier may be scrambled to a        CRC;    -   a bitmap of RBs used for transmitting E-PDCCH and E-PDSCH or        frequency resource information used for transmitting the E-PDCCH        and the E-PDSCH, for example, a range of a resource region where        control information is allocated or a range of RBs where at        least one data stream is allocated, the range of the resource        region or the range of the RBs includes information associated        with a range of a resource region, a range of a limited resource        region when RBs are limited, or a range of limited RBs;    -   a number of OFDM symbols or time resource information used for        transmitting the E-PDCCH, for example, a range of a resource        region where control information is allocated;    -   information associated with a location and a pilot pattern, such        as a reference signal (RS) pattern, used for demodulation;    -   power offset;    -   a number of layers of the E-PDCCH;    -   other information associated with the E-PDCCH; and the like.

Examples of the other information associated with the E-PDCCH mayinclude, for example, information associated with a transport format,such as a CCE aggregation level.

For example, the Group C-RNTI may be transmitted after being scrambledto the CRC or may be separately transmitted. The general terminal maynot be able to decode the common control information because the groupC-RNTI included in the common control information, for example, DCI forthe E-PDCCH, may be different from a terminal identifier of thecorresponding terminal. A terminal used for deciding the E-PDCCH fromamong the enhanced terminals may be aware of the group C-RNTIinformation, and thus, may successfully decode the common controlinformation allocated to the corresponding group C-RNTI in the samemanner as a scheme of decoding the PDDCH. As an example, the 3GPP LTEsystem may use a blind decoding scheme.

When a transmission frame having a semi-static format is used, forexample, the format of FIG. 6 is used, the common control informationmay be transmitted via a predetermined broadcast channel (BCH) or otherchannels.

FIG. 2 illustrates an example of a dynamic format of a control channeltransmission frame to support an enhanced terminal.

Referring to FIG. 2, a base station may simultaneously support a generalterminal and an enhanced terminal using a transmission frame having aformat of FIG. 2. For example, a Physical Control Format IndicatorChannel (PCFICH) 210 and a PDCCH 220 transmitted during three symbolperiods may be control channels based on a 3GPP LTE standard. Forexample, the PCFICH 210 may be a channel used for transmittinginformation associated with control channel format indicator (CCFI)indicating a location of the PDCCH, and the PDCCH 220 may transmitinformation associated with a number of transmitted symbols for thePDCCH 220. The PDCCH 220 may transmit, to each terminal, controlinformation, such as resource allocation information associated with aresource transmitted to a corresponding terminal.

For example, a plurality of candidates for a length of a DCI transmittedto each terminal may exist and a plurality of candidates for a size of aphysical resource CCE occupied for transmitting the DCI may exist.Information thereof may not be separately transmitted. For example, eachterminal may attempt to decode all possible combinations of theplurality of candidates, until succeeding in decoding the DCI. Aterminal identifier, for example, a C-RNTI, of the terminal to which theresource is to be allocated may not be included in the DCI and theC-RNTI may be transmitted after being scrambled to the CRC.

The general terminal, such as a 3GPP LTE terminal, may obtain controlinformation by receiving, for example, the PCFICH 210 and the PDCCH 220transmitted during an initial period of the frame.

The base station may have two schemes to transmit control information toan enhanced terminal, such as an LTE-Advanced terminal.

As a first example, the base station may transmit the controlinformation to the enhanced terminal based on the PCFICH 210 and thePDCCH 220 which are control channels of the general system, such as the3GPP LTE system. In this example, a new control message to support a newtransmission mode of an enhanced system may be additionally used. Forexample, a logical control message may be additionally used withoutchanging a control channel of a 3GPP LTE standard, and thus, a change ina standard associated with an E-PDCCH, such as a control channel of aLTE Advanced system, may be minimized.

As a second example, the base station may transmit the controlinformation using an E-PDCCH 240. In this example, control informationassociated with an E-PDSCH 250 where data streams are allocated, may betransmitted based on the E-PDCCH 240. For example, common controlinformation 221 that the enhanced terminal uses for decoding the E-PDCCH240 may be transmitted using the general control channel such as PDCCH220. In this example, the base station may perform one ofspatial-multiplexing, beamforming, and a beamforming-basedspatial-multiplexing of the control information, such as the DCI for theE-PDSCH, transmitted using via E-PDCCH 240, as described above. Forexample, the general terminal may receive the control informationassociated with the PDSCH 230, using the PDCCH 220. Accordingly, atransmission efficiency of the control information associated with theenhanced terminal may be improved, a decoding complexity of the E-PDCCH240 may be minimized, and amount of the common control information 221,such as the DCI for the E-PDSCH, may be reduced.

FIG. 3 illustrates a second example of a dynamic format of a controlchannel transmission frame to support an enhanced terminal.

Referring to FIG. 3, with respect to the E-PDCCH 340 and the E-PDSCH 350being transmitted based on the same RBs, a number of layers of theE-PDCCH 340 may not always be the same as a number of layers of theE-PDSCH 350, and the E-PDCCH 340 transmitted through a predetermined RBsmay not always transmit allocation information associated with theE-PDSCH 350 transmitted through the corresponding RB. For example, theE-PDCCH 340 may allocate control information associated with anotherE-PDSCH in addition to control information associated with the E-PDSCH350 that uses the same RBs as the RBs of the E-PDCCH 340.

A portion 351 of RBs for the E-PDSCH 350, for example, the RBscorresponding to the RBs of the E-PDCCH 340, may not be used asillustrated in FIG. 3. For example, the common control information 321may show a range of the RBs used for transmitting the E-PDCCH 340 andthe E-PDSCH 350 using a bitmap. As an example, the range of the RBs usedfor transmitting the E-PDCCH 340 and the E-PDSCH 350 may be a supersetof a range of RBs that may be occupied by the E-PDCCH 340 and theE-PDSCH 350. A spatial-layer of the E-PDCCH 340 and a spatial-layer ofthe E-PDSCH 350 may be different.

FIG. 4 illustrates a third example of a dynamic format of a controlchannel transmission frame to support an enhanced terminal.

Referring to FIG. 4, a portion 441 of RBs for an E-PDCCH 440, forexample, the RBs corresponding to an RBs of an E-PDSCH 450, may not beused similar to the example shown in FIG. 3.

FIG. 5 illustrates an example of a control information transmissionmethod of a base station based on the dynamic format of the controlchannel transmission frame of FIG. 2.

Referring to FIG. 5, a base station determines whether to use an E-PDCCHin 510. When the base station determines not to use the E-PDCCH, thebase station allocates RBs to data streams, in 520, and transmitscontrol information using a PDCCH that is a control channel of a generalsystem, in 530.

When the base station determines to use the E-PDCCH, the base stationtransmits a group terminal identifier, such as a group C-RNT, to one ormore enhanced terminals, in 540. Transmission of the group terminalidentifier has been previously described. The transmission of the groupterminal identifier may be omitted in a subsequent period. The basestation may allocate RBs to at least one data stream transmitted via anE-PDSCH, in 550. For example, the base station may allocate the controlinformation associated with the RBs allocated to the at least one streamtransmitted via the E-PDSCH, to the same resource region for theE-PDCCH. For example, the base station may perform one ofspatial-multiplexing, beamforming, and beamforming spatial-multiplexingof the E-PDCCH. The base station may allocate common controlinformation, such as DCI for the E-PDCCH, used for decoding the E-PDCCH.This process has been described with reference to FIG. 1.

When the allocation is completed, the base station transmits, using thePDCCH, the common control information used for decoding the E-PDCCHusing the PDCCH, in 560. The base station transmits, using the E-PDCCH,the control information, such as DCI for an E-PDSCH, which is one ofspatial-multiplexed, beamforming-processed, and beamforming-basedspatial-multiplexed, in 570.

Accordingly, the base station may simultaneously support the generalterminal and the enhanced terminal, using the transmission frame of FIG.2, and may transmit the control information by selecting a controlchannel used for transmitting the control information based on whetherthe E-PDCCH is to be used.

FIG. 6 illustrates an example of a semi-static format of a controlchannel transmission frame to support an enhanced terminal.

Referring to FIG. 6, a base station may transmit an E-PDCCH 640 using asemi-statically allocated resource. For example, the semi-staticallyallocated resource may vary according to a predetermined resource orinformation transmitted based on a super frame unit. The base stationmay transmit common control information used for decoding the E-PDCCH640 without using a PDCCH 620 or a PCFICH 610. Information correspondingto the common control information may be transmitted, for example, via aseparate BCH or a predetermined channel of an upper layer. Therefore,the enhanced terminal may not be able to decode the PCFICH 610 or thePDCCH 620 which are the control channels of the general system.

In some embodiments, the length of the PDCCH 620 may be different foreach frame. Accordingly, when a transmission location from which theE-PDCCH 640 is transmitted, is arranged in a front part of a frame, theE-PDCCH 640 may overlap with the PDCCH 620. For example, a locationafter a maximum symbol length occupied by the PDCCH 620 may bedetermined as the transmission location of the E-PDCCH 640. For example,a symbol after a fifth symbol may be determined as the transmissionlocation of the E-PDCCH 640, based on the 3GPP LTE standard. As anotherexample, a symbol after a symbol allocated to the E-PDCCH may transmitE-PDSCH 650.

The control information associated with the general terminal may betransmitted via the PDCCH 620, and data of the general terminal may beallocated to a region of the PDSCH 630.

Accordingly, an enhanced terminal may also decode a PDCCH, such as acontrol channel of a 3GPP LTE system, when the transmission frame in theexample of FIG. 2 is used. However, when the transmission frame in theexample of FIG. 6 is used the enhanced terminal may transmit the commoncontrol information without using the PDCCH 620, and thus, the enhancedterminal may not be able to decode the PDCCH 620.

FIG. 7 illustrates an example of a control information transmissionmethod of a base station based on the semi-static format of the controlchannel transmission frame of FIG. 6.

Referring to FIG. 7, a base station allocates RBs to data streams, in710. An example of allocating RBs is described with reference to FIG. 1.The base station determines whether to use a control channel of anenhanced system such as an E-PDCCH, in 720.

When the base station determines to not use the E-PDCCH, the basestation transmits control information via a control channel of a generalsystem such as a PDCCH, in 730.

When the base station determines to use the E-PDCCH, the base stationtransmits the control information via an E-PDCCH existing in apredetermined location, in 740. An example of transmitting the E-PDCCHusing a semi-statically allocated resource is described with referenceto FIG. 6.

Accordingly, when the transmission frame of FIG. 6 is used, the basestation may simultaneously support a general terminal and an enhancedterminal based on the method of FIG. 7, and may transmit the controlinformation by selecting a control channel to transmit the controlinformation based on whether the E-PDCCH is to be used. While using theE-PDCCH, the base station may utilize a semi-statically allocatedresource, and thus, the base station may not be able to decode thePDCCH.

Methods for Improving a Transmission Efficiency of an E-PDCCH

Three examples for improving the transmission efficiency of the E-PDCCHare provided.

In a first example, a base station may perform one ofspatial-multiplexing, beamforming, and beamforming-basedspatial-multiplexing with respect to an E-PDCCH of the same physicalresource. The base station may transmit, to a single terminal or aplurality of terminals, the E-PDCCH that is one of spatial-multiplexed,beamforming-processed, and beamforming-based spatial-multiplexed.Accordingly, a transmission efficiency of control information may beimproved. This method is described with reference to FIG. 1.

A second example may limit a resource occupied by the EPDCCH and anE-PDSCH and transmit corresponding information to a terminal.

For example, bitmap information of RBs used for transmitting the E-PDCCHand the E-PDSCH may be information associated with a set of RBs that theE-PDCCH and the E-PDSCH may occupy from among all of the RBs. In thisexample, when the transmission frame having a dynamic format of FIG. 2is used, corresponding bitmap information of RBs may be included in thecommon control information, such as the DCI for the E-PDCCH, and may betransmitted via the PDCCH. As another example, when the transmissionframe having a semi-static format is used, the corresponding bitmapinformation of RBs may be transmitted via a separate BCH or via apredetermined channel of an upper layer.

Overhead may decrease based on the second method, compared with theexample of indicating a resource allocated to the E-PDCCH from among allof the RBs. For example, when total number of RBs is 100 and a bitmap isallocated for every fourth RB, a length of an RB assignment bitmap is 25bits. However, when the number of RBs for the E-PDCCH and the E-PDSCH islimited to 40, the length of the RB assignment bitmap included in theDCI transmitted via the E-PDCCH may be shortened. For example, thelength of the RB bitmap may be shortened to 10 bits.

A third example may match a physical resource occupied by the E-PDCCH toa physical resource occupied by an enhanced data transmission channel,such as the E-PDSCH, corresponding to the E-PDCCH. For example, the basestation may allocate control information to overlap a resource regionfor the E-PDCCH to a region of RBs where the data streams are allocated.

When the control information is transmitted via the PDCCH, a mappingrelation between a basic physical resource unit used for transmittingthe PDCCH and the RBs where the data streams are allocated may notexist. Although information associated with RBs used for transmittingthe PDSCH may be recognized, information associated with a CCE used forallocating a corresponding PDCCH may not be recognized. In anotherexample, although information associated with a CCE used fortransmitting the PDCCH is recognized, information associated with RBsused for transmitting the PDSCH may not be recognized. However, acontrol information transmission method of the enhanced system may matcha range of a resource region occupied by the E-PDCCH to a range of RBsoccupied by the E-PDSCH, as illustrated in FIG. 2. As described above, aterminal may recognize a physical resource occupied by the E-PDCCH andthe E-PDSCH based on information associated with a limitation of RBsincluded in the common control information. In this example, the controlinformation may be the DCI for the E-PDCCH, information transmitted viaa BCH, or a predetermined channel of an upper layer. An example thereofis described with reference to FIG. 8.

FIG. 8 illustrates an example of a format of a transmission frame wherea CCE used for transmitting E-PDCCH and an RB used for transmittingE-PDSCH are mapped.

Referring to FIG. 8, mapping between a CCE 810 used for transmitting anE-PDCCH and an RB 820 used for transmitting the E-PDSCH may bedetermined based on a predetermined rule, for example, one RB per CCE.For example, when information associated with limitation of RBs used fortransmitting the E-PDSCH is transmitted via common control informationassociated with CCEs used for decoding the E-PDCCH, and informationassociated with arrangement of the CCEs may be obtained.

For example, the common control information may include bitmapinformation of RBs used in the E-PDCCH and the E-PDSCH, and each bitmapmay indicate the number of RBs that are allocated. When the enhancedterminal decodes the bitmap information of RBs, the enhanced terminalmay recognize that RBs used for transmitting the E-PDSCH aresequentially mapped to CCEs, and the number of RBs used for transmittingthe E-PDSCH and the number of symbols used for transmitting the E-PDCCH,are the same. The enhanced terminal may also recognize informationassociated with a resource region that transmits E-PDCCH, withoutadditional information associated with a number of CCEs.

Method for Decreasing a Decoding Complexity with Respect to a ControlChannel of a Terminal in an Enhanced System Selectively Decoding a PDCCHor an E-PDCCH Using an Indicator

When common control information used for decoding the E-PDCCH istransmitted using the transmission frame of FIG. 2 or using the PDCCHbased on the control information transmission method of FIG. 5, RBassignment information with respect to an enhanced terminal may betransmitted via the PDCCH or the E-PDCCH. In this example, the enhancedterminal may attempt to decode both the PDCCH and the E-PDCCH based onboth probabilities, and thus, a decoding complexity may increase.

Accordingly, methods for decreasing the decoding complexity may be used.As an example, when the enhanced terminal initially receives a resourceallocated from a base station, it may be predetermined that the enhancedterminal receives control information from a predetermined controlchannel from among the PDCCH and the E-PDCCH, for example, from aninitially predetermined control channel. When the indicator associatedwith a location about where control information is to be allocatedduring and after a subsequent resource allocation period, istransmitted, decoding may be performed with respect to one of the PDCCHand the E-PDCCH. Accordingly, the decoding complexity may decrease.

For example, the indicator may indicate a channel to be used during thesubsequent allocation period for transmitting resource allocationinformation such as control information. For example, the indicator maybe included in a control message, such as DCI for the E-PDSCH which istransmitted via the E-PDCCH for the enhanced terminal. As anotherexample, the indicator may be included in a control message, such as DCIfor the PDSCH which is transmitted via the PDCCH for the enhancedterminal. In these examples, the decoding complexity with respect to thecontrol channel of the enhanced terminal may decrease. For example, whenthe enhanced terminal recognizes that the resource allocationinformation is to be transmitted via the PDCCH, the enhanced terminalmay not attempt decoding of the DCI for E-PDCCH and the E-PDCCH, andwhen the enhanced terminal recognizes that the resource allocationinformation is to be transmitted via the E-PDCCH, the enhanced terminalmay not attempt decoding of DCI that is transmitted to a correspondingterminal, from among the PDCCH.

For example, the indicator may directly indicate a channel, such asindicating the PDCCH as ‘0’ or indicating the E-PDCCH as ‘1’. As anotherexample, the indicator may indicate whether a control channel used in asubsequent resource allocation period is to be changed as compared witha control channel used in a current resource allocation period. Forexample, a state of being changed may be indicated as ‘1’ and a state ofnot being changed is indicated as ‘0’.

Channels of the general system, such as the PDCCH and a PDSCH, andchannels of the enhanced system, such as the E-PDCCH and an E-PDSCH, maybe dynamically utilized. For example, when a desired capacity of a datachannel is high and a desired capacity of a control channel is low, theE-PDSCH may be used as the data channel and the PDCCH may be used as acontrol channel. Accordingly, a wide region for the data channel may beutilized. In this example, the indicator may indicate a channel to beused, such as the PDCCH or the E-PDCCH, for an asymmetric loading factorof the data channel and the control channel. Accordingly, the enhancedterminal may dynamically handle data transmission.

FIG. 9A illustrates an example of a control information reception methodof an enhanced terminal.

Referring to FIG. 9A, the enhanced terminal determines whether theenhanced terminal initially receives a resource allocated from a basestation, in 910.

When it is an initial time for the enhanced terminal to receive theresource allocated from the base station, the enhanced terminal mayreceive control information via a predetermined channel from among aPDCCH and an E-PDCCH. Referring to FIG. 9A, the predetermined controlchannel is the PDCCH. In 920, the enhanced terminal decodes the PDCCH toobtain control information. In 921, the enhanced terminal determineswhether the resources are allocated based on the decoded resourceallocation information. Based on whether the resources are determined tobe allocated in 921, the enhanced terminal waits for a subsequentresource allocation period, in 922, or the enhanced terminal receivesdata via a data channel, such as a PDSCH or an E-PDSCH, in 923. Theenhanced terminal obtains information associated with a control channelthat may transmit control information during the subsequent resourceallocation period, in 924.

When it is not the initial time for the enhanced terminal to receive theresource allocated, the enhanced terminal determines whether to use theE-PDCCH for transmitting the control information, in 930. For example,the enhanced terminal may extract a previous indicator included incontrol information received during a previous resource allocationperiod and may determine whether to use the E-PDCCH based on theindicator. When the determination determines not to use the E-PDCCH, theenhanced terminal decodes the PDCCH in 920, and subsequently 921 isperformed.

When the determination of 930 determines to not use the E-PDCCH, theenhanced terminal obtains common control information used for decodingthe E-PDCCH, in 931.

For example, the common control information may be obtained by theenhanced terminal by decoding the common information based on a groupterminal identifier, such as a group C-RNTI, which may be commonlyallocated to all terminals in an enhanced system. In this example, whenthe transmission frame having a dynamic format of FIG. 2 is used, thecommon control information may be transmitted via the PDCCH.Accordingly, the enhanced terminal may obtain the common controlinformation by decoding the PDCCH. The common control information mayinclude the group terminal identifier, such as the Group C-RNTI, asdescribed above.

For example, when the transmission frame having a semi-static format ofFIG. 6 is used, the common control information may be received via thepredetermined channel. The predetermined channel may be a separate BCHor may be other channels. Therefore, the enhanced terminal may obtainthe common control information via the predetermined channel.

Subsequently, the enhanced terminal determines whether decoding of acontrol channel during the previous resource allocation period fails, in940.

When the decoding of the control channel during the previous resourceallocation period fails, the enhanced terminal may not be able todetermine whether the control information is to be transmitted via thePDCCH or via the E-PDCCH, during the subsequent resource allocationperiod. To overcome this problem, the enhanced terminal that fails indecoding the control channel may decode both the PDCCH and the E-PDCCHfor a predetermined number of times. When allocated control informationdoes not exist even after performing the multiple decoding attempts, theenhanced terminal may attempt decoding of only an initiallypredetermined control channel. This may be referred to as a fall backmode of a terminal that fails in decoding. When the base station failsto receive feedback, such as an acknowledgment (ACK) or negativeacknowledgment (NACK), the ACK and NACK being associated with a resultof the decoding even when the base station allocates a resource, atleast a predetermined number of times, the base station may transmit theinitially predetermined control channel, such as the PDCCH or theE-PDCCH a subsequent time where the base station allocates the resource.

Whether the E-PDCCH is transmitted is determined in 941. When the PDCCHis received, the enhanced terminal proceeds with operation 920 to decodethe PDCCH. When the E-PDCCH is received, the enhanced terminal decodesthe E-PDCCH based on a blind decoding scheme in 950. The enhancedterminal waits for the subsequent resource allocation period, in 970.

Method of Decreasing Blind Decoding Complexity with Respect to E-PDCCH

FIG. 9B illustrates a process of decoding an E-PDCCH based on a blinddecoding scheme. Referring to FIG. 9B, operation 950 in FIG. 9A isfurther described.

Referring to FIG. 9B, an enhanced terminal may be allocated to the sameresource region, for example, the resource region being for the E-PDCCH.The enhanced terminal may receive control information that is one ofspatial-multiplexed, beamforming performed, and beamforming-basedspatial-multiplexed. The control information is information associatedwith RBs allocated to at least one data stream transmitted via anE-PDSCH. When the enhanced terminal decodes a plurality of candidatesassociated with control information, based on the blind decoding scheme,the enhanced terminal may decrease a decoding complexity based onfollowing methods.

When a plurality of E-PDCCHs are transmitted after being one ofspatial-multiplexed, beamforming-processed, and beamforming-basedspatial-multiplexed, based on the same time frequency resource, each ofthe plurality of E-PDCCHs may use a different dedicated RS, such asDM-RS. The enhanced terminal may not recognize a port to be allocated toa target enhanced terminal, from among a plurality of streams that isone of spatial-multiplexed, beamforming-processed, and beamforming-basedspatial-multiplexed. Therefore, the enhanced terminal may perform blinddecoding with respect to all ports. For example, a number of candidatesthat are to be targets of the blind decoding may increase in proportionto a number of layers. As a result, the control channel decodingcomplexity of the enhanced terminal may increase. For example, when fourstreams where different control information is encoded arespatial-multiplexed and transmitted, the enhanced terminal may notrecognize a layer to be allocated to the corresponding terminal, andthus, the enhanced terminal may attempt decoding with respect to alllayers.

Methods to decrease the blind decoding complexity are providedhereinafter. When a scheduling is performed, the E-PDCCH may have a highpossibility of being transmitted via a spatial-layer that has a superiorsignal to noise ratio (SNR) in a receiving terminal. Therefore, in 951the enhanced terminal estimates a reception SNR based on RSs for eachlayer before performing the blind decoding. For example, the enhancedterminal may be decoded in an order of highest SNR to lowest SNR. Theenhanced terminal may start decoding of a first layer, in 952. Theenhanced terminal determines an entire CCE candidate set, in 953,calculates a PB power for each layer, in 954, and performs blinddecoding with respect to the entire CCE candidate set in the order ofhighest SNR to lowest SNR, in 955. In 956, whether the blind decoding issuccessful for that respective layer is determined.

If not successful, the enhanced terminal performs blind decoding withrespect to the entire CCE candidate set, in 957. When the blind decodingfails, the enhanced terminal performs blind decoding with respect to alayer having a second highest SNR, for example a subsequent layer, in958. In this manner, a sequence of the decoding may be determined, andsubsequent layers are decoded until decoding of all the layers iscompleted, in 959. For example, an SNR of a spatial-layer allocated tothe corresponding enhanced terminal may be high, and thus, the decodingcomplexity may dramatically decrease when decoding is performed based ona priority.

When decoding with respect to a predetermined layer succeeds in 956, theenhanced terminal may obtain, through an indicator included in controlinformation, information associated with a control channel where thecontrol information is to be transmitted during a subsequent resourceallocation period, in 960. Data is received via the E-PDSCH, in 961.

The enhanced terminal may perform blind decoding until a predeterminednumber of control information are successfully decoded. For example, theenhanced terminal may perform decoding with respect to layers in anorder of highest SNR to lowest SNR, until the same number of controlinformation as a number of control information to be allocated to theenhanced terminal is successfully decoded, and when the predeterminednumber of control information is successfully decoded, the enhancedterminal may stop decoding.

FIG. 10 illustrates an example of a transmitter that simultaneouslysupports a general terminal and an enhanced terminal.

Referring to FIG. 10, the transmitter that simultaneously supports ageneral terminal and an enhanced terminal includes a scheduler 1010, aspatial-multiplexer 1020, and a transmission module 1030.

The scheduler 1010 may allocate RBs to at least one data streamtransmitted via an E-PDSCH, may generate control information for each ofthe RBs, and may allocate the control information for each of the RBs tothe same resource region. For example, the resource region may be for anE-PDCCH.

The spatial-multiplexer 1020 may perform, based on the same resourceregion, one of beamforming, spatial-multiplexing, and beamforming-basedspatial-multiplexing with respect to the control information for each ofthe RBs.

The transmission module 1030 may transmit, to each terminal, the controlinformation that is one of beamforming-processed, spatial-multiplexed,and beamforming-based spatial-multiplexed.

FIG. 11 illustrates an example of an enhanced terminal.

Referring to FIG. 11, the enhanced terminal includes a reception module1110, a memory 1120, and a processor 1130.

The reception module 1110 may receive control information and datastreams from a base station.

The memory 1120 may store a previous indicator included in controlinformation received during a previous resource allocation period.

The processor 1130 determines, based on the previous indicator, achannel used for transmitting target control information, for example,from among an E-PDCCH and a PDCCH, and performs decoding with respect tothe target control information based on the determination.

The transmitter and the receiver have been described with reference toFIGS. 10 and 11. It should be understood that the examples describedwith reference to FIGS. 1 through 9 may be applicable to the transmitterand the receiver.

As a non-exhaustive illustration only, the terminal device, that is, thetransmitter and/or the receiver, described herein may refer to mobiledevices such as a cellular phone, a personal digital assistant (PDA), adigital camera, a portable game console, an MP3 player, aportable/personal multimedia player (PMP), a handheld e-book, a portablelab-top personal computer (PC), a global positioning system (GPS)navigation, and devices such as a desktop PC, a high definitiontelevision (HDTV), an optical disc player, a setup box, and the like,capable of wireless communication or network communication consistentwith that disclosed herein.

A computing system or a computer may include a microprocessor that iselectrically connected with a bus, a user interface, and a memorycontroller. It may further include a flash memory device. The flashmemory device may store N-bit data via the memory controller. The N-bitdata is processed or will be processed by the microprocessor and N maybe 1 or an integer greater than 1. Where the computing system orcomputer is a mobile apparatus, a battery may be additionally providedto supply operation voltage of the computing system or computer.

It should be apparent to those of ordinary skill in the art that thecomputing system or computer may further include an application chipset,a camera image processor (CIS), a mobile Dynamic Random Access Memory(DRAM), and the like. The memory controller and the flash memory devicemay constitute a solid state drive/disk (SSD) that uses a non-volatilememory to store data.

The above-described methods, processes, functions, and/or software maybe recorded in a computer-readable storage media including programinstructions to implement various operations embodied by a computer. Themedia may also include, alone or in combination with the programinstructions, data files, data structures, and the like. Examples ofcomputer-readable storage media include magnetic media such as harddisks, floppy disks, and magnetic tape; optical media such as CD ROMdisks and DVDs; magneto-optical media such as optical disks; andhardware devices that are specially configured to store and performprogram instructions, such as read-only memory (ROM), random accessmemory (RAM), flash memory, and the like. Examples of programinstructions include both machine code, such as produced by a compiler,and files containing higher level code that may be executed by thecomputer using an interpreter. The described hardware devices may beconfigured to act as one or more software modules in order to performthe operations of the above-described example embodiments, or viceversa. In addition, the computer-readable storage medium may bedistributed among computer systems connected through a network andcomputer-readable codes or program instructions may be stored andexecuted in a to decentralized manner.

A number of examples have been described above. Nevertheless, it shouldbe understood that various modifications may be made. For example,suitable results may be achieved if the described techniques areperformed in a different order and/or if components in a describedsystem, architecture, device, or circuit are combined in a differentmanner and/or replaced or supplemented by other components or theirequivalents. Accordingly, other implementations are within the scope ofthe following claims.

What is claimed is:
 1. A transmission method, comprising: transmitting,to terminals supported by an enhanced system, a group terminalidentifier of the terminals; allocating resource blocks (RBs) to atleast one data stream transmitted via an enhanced-physical downlinkshared channel (E-PDSCH); generating control information for each of theRBs; allocating the control information for each of the RBs to aresource region for an enhanced-physical downlink control channel(E-PDCCH); and performing beamforming, or spatial-multiplexing, orbeamforming-based spatial-multiplexing, of the control information foreach of the RBs, based on the resource region, wherein a type 1 terminalsucceeds in decoding the control information received via the E-PDCCH,and a type 2 terminal does not decode, or fails in decoding, the controlinformation received via the E-PDCCH, and is supported by a differenttype of system than the type 1 terminal.
 2. The transmission method ofclaim 1, further comprising: generating an indicator indicating whetherthe E-PDCCH is used in a subsequent resource allocation period, whereinthe control information for each of the RBs comprises the indicator. 3.The transmission method of claim 1, wherein the resource region is usedto transmit the control information for each of the RBs, and is aportion of a physical resource used by the E-PDSCH.
 4. The transmissionmethod of claim 1, further comprising: generating common controlinformation used to decode the control information for each of the RBs;and transmitting the common control information via a physical downlinkcontrol channel (PDCCH).
 5. The transmission method of claim 4, whereinthe common control information comprises information associated with arange of the resource region to which the control information for eachof the RBs is allocated, or information associated with a range of theRBs to which the at least one data stream is allocated, or the groupterminal identifier of the terminals where decoding of the E-PDCCH is tobe performed, or information associated with a location and a pilotpattern for demodulation, or information associated with a power offset,or information associated with a transport format, or any combinationthereof.
 6. The transmission method of claim 4, wherein: the allocatingof the RBs comprises allocating a portion of all RBs to the at least onedata stream; the allocating of the control information comprisesallocating the control information for each of the RBs to a portion ofan entire resource region for the E-PDCCH; and the common controlinformation comprises information associated with the portion of all theRBs, and information associated with the portion of the entire resourceregion.
 7. The transmission method of claim 4, further comprising:allocating the common control information to a predetermined resourceregion for the PDCCH, wherein both the type 1 terminal and the type 2terminal successfully decode information received via the PDCCH.
 8. Thetransmission method of claim 7, wherein: the type 1 terminal issupported by the enhanced system; and the type 2 terminal is supportedby a general system.
 9. The transmission method of claim 1, furthercomprising: generating common control information used to decode thecontrol information for each of the RBs; and transmitting the commoncontrol information via a predetermined broadcast channel.
 10. Thetransmission method of claim 9, wherein the common control informationcomprises information associated with a range of the resource region towhich the control information for each of the RBs is allocated, orinformation associated with a range of the RBs to which the at least onedata stream is allocated, or the group terminal identifier of theterminals where decoding of the E-PDCCH is to be performed, orinformation associated with a location and a pilot pattern fordemodulation, or information associated with a power offset, orinformation associated with a transport format, or any combinationthereof.
 11. The transmission method of claim 9, wherein: the allocatingof the RBs comprises allocating a portion of all RBs to the at least onedata stream; the allocating of the control information comprisesallocating the control information for each of the RBs to a portion ofan entire resource region for the E-PDCCH; and the common controlinformation comprises information associated with the portion of all theRBs, and information associated with the portion of the entire resourceregion.
 12. The transmission method of claim 1, wherein the controlinformation comprises information associated with a range of the RBs towhich the at least one data stream is allocated, or informationassociated with a number of the at least one data stream, or a terminalidentifier of a terminal to which the control information is allocated,or location information and a pilot pattern for demodulation, orinformation associated with a power offset, or information associatedwith a co-scheduled terminal, or H-ARQ information, or informationassociated with a modulation and coding scheme, or any combinationthereof.
 13. The transmission method of claim 1, wherein the resourceregion overlaps a region of the RBs to which the at least one datastream is allocated.
 14. The transmission method of claim 1, wherein:the type 1 terminal is supported by the enhanced system; and the type 2terminal is supported by a general system.
 15. A transmitter,comprising: a transmission module configured to transmit, to terminalssupported by an enhanced system, a group terminal identifier of theterminals; a scheduler configured to allocate resource blocks (RBs) toat least one data stream transmitted via an enhanced-physical downlinkshared channel (E-PDSCH), generate control information for each of theRBs, and allocate the control information for each of the RBs to aresource region for an enhanced-physical downlink control channel(E-PDCCH); and a spatial-multiplexer configured to perform beamforming,or spatial-multiplexing, or beamforming-based spatial-multiplexing, ofthe control information for each of the RBs, based on the resourceregion, wherein a type 1 terminal succeeds in decoding the controlinformation received via the E-PDCCH, and a type 2 terminal does notdecode, or fails in decoding, the control information received via theE-PDCCH, and is supported by a different type of system than the type 1terminal.
 16. The transmission method of claim 1, wherein a portion ofthe RBs allocated to the at least one data stream transmitted via theE-PDSCH is not used.
 17. The transmission method of claim 1, wherein aportion of the resource region for the E-PDCCH is not used.
 18. Thetransmission method of claim 4, wherein the common control informationcomprises the group terminal identifier of the terminals.
 19. Thetransmission method of claim 4, wherein the terminals receive the groupterminal identifier and the common control information, and decode thecommon control information based on the received group terminalidentifier.